Replaceable drill bit nozzles



Nov. 30, 1965 TAKESHI MORI REPLACEABLE DRILL BIT NOZZLES Filed Aug. 26, 1963 INVENTOR. Z /KEs/w M02! fir raeusy.

United States Patent Office Patented Nov. 3%, 1965 3,220,754 REPLACEABLE BRELL BET NOZZLES Takeshi Mari, Salt Lake City, Utah, assignor to Christensen Diamond Products Company, Salt Lake City, Utah, a corporation of Utah Filed Aug. 26, 1963, Ser. No. 304,531 3 Saints. (til. 285-365) The present invention relates to rotary drill bits for drilling oil, gas, and similar well bores and more particularly to rotary drill bits having replaceable nozzles through which drilling fluid can be discharged, for the purposes of maintaining the bit in a clean and cool condition and flushing the cutting from the cutting region and securing their conveyance to the top of the well bore.

Heretoiore, replaceable nozzles have been held in place in drill bits by holding devices which are subject to erosion of the fluid discharged from the nozzles, oftentimes resulting in failure of the holding device and loss of the nozzle while the bit is in the well bore. In addition, prior nozzle holding devices have been diflicult to install and also difficult to remove in the event nozzle replacement is required. The holding devices have also entailed somewhat complex machining requirements in connection with production of the bit.

Accordingly, it is an object of the present invention to provide a well drilling bit embodying a replaceable nozzle secured in place by a holding which is protected from fluid erosion, particularly from the erosion of the fluid discharged from the nozzle.

Another object of the invention is to provide a well drilling bit embodying a replaceable nozzle, in which assembly of the nozzle in the bit and its removal therefrom can be accomplished in a very easy manner. Only elemental hand tools need be used.

A further object of the invention is to provide a well drilling bit embodying a replaceable nozzle secured in place by a comparatively simple holding mechanism, which can be manufactured in an easy manner and with comparatively simple machine tools.

This invention possesses many other advantages, and has other objects which may be made more clearly apparent from a consideration of a form in which it may be embodied. This form is shown in the drawings ac companying and forming part of the present specification. It will now be described in detail, for the purpose of illustrating the general principles of the invention; but it is to be understood that such detailed description is not to be taken in a limiting sense, since the scope of the invention is best defined by the appended claims.

Referring to the drawings:

FIGURE 1 is a longitudinal section through a drill bit embodying the invention;

FIG. 2 is an enlarged fragmentary longitudinal section through a fluid discharge portion of the bit disclosed in FIG. 1;

FIG. 3 is a section taken along the line 3-3 on FIG. 2 with the lock or retaining pin in place;

FIG. 4 is a view similar to FIG. 3 disclosing the manner of removing the lock or retaining pin from the drill bit.

The invention is illustrated in the drawings as embodied within a rotary drill bit A of the drag type. It is to be understood, however, that it is usable in connection with other types of drill bits, such as roller drill bits and bits of the expansible type, from which drilling fluid is to be ejected.

As specifically illustrated, the drill bit includes a main body having an upper threaded box 10a for threaded attachment to the lower end of a string of drill pipe B extending to the top of the well bore and by means of which the drill bit is rotated in the hole. The drill bit has a plurality of drag cutters or blades 11 suitably secured thereto, which can operate upon the bottom of the well bore to drill the latter to the requisite diameter. In the specific device illustrated, the drag cutters or blades 11 have their leading faces 12 overlapping each other in contacting relation. During the rotation of the drill bit with the appropriate drilling weight applied to its cutters, drilling fluid is pumped down through the string of drill pipe B and through the central passage 13 in the body, this fluid passing down through a passage 14 in each of the drag blades and discharging therefrom in a downward direction, the drag blade passage having its upper end communicating with the central body passage 13. The passage 14 has a nozzle 15 mounted therewithin made of an erosion resisting material, such as tungsten carbide, and it is from this nozzle that the fluid discharges into the well bore to clean and cool the cutters 11 and flush the drill bit cuttings from the well bore upwardly around the bit and the drill pipe to the top of the hole.

Each nozzle 15 of the drill bit (of which only one is disclosed) is removably mounted in its associated cutter 11 or in the body 10 of the bit. As illustrated, it is movable upwardly into a counterbore 16 in the fluid passage that terminates in an upper shoulder 17 against which the nozzle can abut. Leakage of fluid between the exterior of the nozzle and the wall of the counterbore is prevented by a suitable side seal ring 18, such as a rubber or rubber-like O-ring, mounted in a peripheral groove 19 in the nozzle and sealingly engaging the wall of the counterbore.

The nozzle 15 is held in appropriate position in the bit and within its counterbore 16 by a lock or retaining pin 20 disposed within a straight hole 21 in the bit body or blade 11, which intersects a transverse external groove or slot 22 in the nozzle, such as the chordal groove illustrated most clearly in FIGS. 3 and 4. The hole or bore 21 in the bit body or blade has an inlet 23 at an exposed face 24 of the blade into which the retaining pin can be inserted, and also an outlet 25 that opens into a larger straight hole 26 opening outwardly of the cutter blade or bit body 11 through another exposed face 27, this larger hole being disposed at an obtuse angle to the smaller hole 21. The inner portion 28 of the retaining pin 20 is received in the larger bore 26 and its end 29 is pointed or tapered so that the pin, after shifting inwardly through the smaller hole 21, will engage the opposite wall 30 of the larger hole and be bent or deflected in an outward direction, thereby securing the pin in place. The pin 20 is made of a malleable metal, such as mild steel, brass, or the like, so as to be readily deflectable when its inner end 29 engages the wall 30 of the larger hole or opening 26 in the bit body or blade.

In assembling the nozzle 15 in the bit, it need merely be inserted upwardly into the counterbore 16 with its seal ring 18 in place and its groove 22 properly aligned or oriented with the smaller hole 21 which opens into and across the counterbore itself. A straight lock or re taining pin 20 0f the appropriate length is then inserted taining pin 20 of the appropriate length is then inserted erably having a diameter conforming to the diameter of the smaller hole, and the pin driven inwardly, as by hammer blows. When the tapered end 29 of the pin engages the wall 39 of the tapered bore, the forward portion 28 of the pin will automatically be bent or deflected in an outward direction. The hammering action on the pin continues until the pin is substantially flush with the outer surface 14 of the blade or bit body 11. The pin is of such length that when it has been driven into the blade or body, its tapered end 29 will still be disposed within the confines of the blade or body, such as illustrated in FIG. 3.

With the retainer pin 20 in place, the nozzle 15 is locked in position and cannot be forced outwardly by the pressure of the fluid being pumped through the passage 14. The downward force imposed on the nozzle is transmitted through the wall of its chordal groove 22 to the pin, and from the pin to the blade or hit body 11. The fluid discharging from the nozzle is prevented from eroding the pin, since the latter is disposed fully within the drag blade or body 11 and is completely protected. Thus, any eddying or turbulence of the fluid in the well bore created by the jet emanating from the nozzle is incapable of effecting any backwashing action on the retainer pin 20 and is incapable of damaging it, the pin remaining in its appropriate assembled position in the drill bit to retain the nozzle 15 in place within its associated passage 14.

The pin 20 cannot move out of its assembled relation, since any tendency for it to move inwardly to a further extent is prevented by engagement of its tapered end 29 with the wall 30 of the bore 26. Any tendency for the pin to move in a reverse direction back through the hole 21 of smaller diameter is prevented by the engagement of the bent forward portion 28 of the pin with the merging corner 32 of the blade or body at the intersection of the small and larger bores 21, 25. Accordingly, the pin 20 is prevented from moving in either direction from its appropriate assembled relation within the bit body 11 and with respect to the nozzle 15.

In the event the nozzle 15 is to be removed, the pin 20 is easily driven from the blade or body. The end of a punch C of an appropriate size (FIG. 4), capable of entering the smaller diameter bore 21, need merely be placed against the end 33 of the pin and such punch struck with a hammer to drive the pin into the larger bore 26 and outwardly therefrom. The malleable pin readily bends until its end 33 is disposed within the larger bore 26, whereupon the pin is free from the drag bit and can be pulled out, or it may pop or drop out of the larger bore. The removal of the punch C from the smaller hole 21 then allows the nozzle 15 to be slipped downwardly out of its counterbore 16 and, if desired, replaced with another nozzle of the same or different internal size, which is locked in place by hammering another malleable retaining pin 20 into the smaller bore 21 which will engage the wall 36 of the larger bore 26 and be bent into the retaining position illustrated in FIG. 3.

The nozzle is easily mounted and locked in appropriate position in the drill bit in the manner described above merely by driving the pin 20 in place with a simple tool, such as a hammer. The driving of the pin in place automatically effects its bending so that it cannot come out of its retaining relation inadvertently. The pin is easily 1 removed whenever removal of the nozzle is desired merely by use of a punch C to drive the pin on through the holes 21, 26. When the end 33 of the pin against which the punch is placed reaches the larger diameter hole 26, it is free and readily removed from the bit. When in its retaining position, the lock pin 20 is fully protected and not subject to fluid erosion. The holes 21, 26 themselves can be easily machined in the drill bit, since it is only necessary to drill them in the blades or body of the tool at the appropriate locations. This can be done in a comparatively simple drill press, avoiding the necessity for employing elaborate machine tool equipment. The groove 22 in the nozzle can be cast therein or easily machined therein. Thus, the locking arrangement is economical to produce.

I claim:

1. A drill bit having a passage for discharging fluid from the bit, a nozzle disposed in the passage and through which fluid is discharged therefrom, said nozzle having an external transverse groove therein, said bit having a first hole aligned with said groove and extending from a first outer surface of the bit to a location beyond said groove, said bit having a second hole of larger crosssection than said first hole intersecting said first hole at a point beyond said groove and opening outwardly through a second outer surface of the bit and disposed at an obtuse angle to said first hole, said obtuse angle facing in a direction away from said nozzle, and a headless retaining pin insertable from said first outer surface into said first hole, groove and second hole to retain said nozzle in said passage, said pin having a first portion in said first hole and groove and a second portion in said second hole bent at a substantial angle to said first portion to hold said pin in said holes and groove, the maximum crosssection of said pin along its length being no greater than the minimum cross-section of said first hole to enable said pin to be shifted completely from said first hole into said second hole for removal from said second hole, the forward end of said second portion being contiguous the wall of said second hole opposite the inner end of said first hole to prevent longitudinal movement of the pin in the hole in one direction and the rear of said second portion at its intersection with said first portion being engageable with the bit at the intersection of said first and second holes to prevent longitudinal movement of said pin in the holes in the opposite direction.

2. A drill bit having a passage for discharging fluid from the bit, a nozzle disposed in the passage and through which fluid is discharged therefrom, said nozzle having an external transverse groove therein, said bit having a first straight hole aligned with said groove and extending from a first outer surface of the bit to a location beyond said groove, said bit having a second straight hole of larger diameter than said first hole intersecting said first hole at a point beyond said groove and opening outwardly through a second outer surface of the bit and disposed at an obtuse angle to said first hole, said obtuse angle facing in a direction away from said nozzle, said second outer surface being transverse of said first outer surface, and a headless generally cylindrical retaining pin of no greater diameter than the diameter of said first hole insertable from said first outer surface into said first hole, groove and second hole to retain said nozzle in said passage, said pin having a first portion in said first hole and groove and a second portion in said second hole bent at a substantial angle to said first portion, the forward end of said second portion being contiguous the wall of said second hole opposite the inner end of said first hole to prevent longitudinal movement of the pin in the holes in one direction and the rear of said second portion at its intersection with said first portion engaging the bit at the intersection of said first and second holes to prevent longitudinal movement of the pin in the holes in the opposite direction, said pin being adapted to be removed through said second hole.

3. A drill bit having a passage for discharging fluid from the bit, a nozzle disposed in the passage and through which fluid is discharged therefrom, said nozzle having an external transverse chordal groove therein, said bit having a first straight hole aligned with said groove and extending from a first outer surface of the bit to a location beyond said groove, said bit having a second straight hole of larger diameter than said first hole intersecting said first hole at a point beyond said groove and opening outwardly through a second outer surface of the bit and disposed at an obtuse angle to said first hole, said obtuse angle facing in a direction away from said nozzle, and a headless generally cylindrical malleable retaining pin inserta'ble from said first outer surface into said first hole, groove and second hole to retain said nozzle in said passage, said pin having a diameter conforming to the diameter of said first hole and having a first portion in said first hole and groove and a second portion in said secand hole bent at a substantial angle to said first portion, the forward end of said second portion being contiguous the wall of said second hole opposite the inner end of said first hole to prevent longitudinal movement of the pin in the holes in one direction and the rear of said second portion at its intersection with said first portion engaging the bit at the intersection of said first and sec- 5 6 0nd holes to prevent longitudinal movement of the pin 3,084,751 4/1963 Scarborough 175-393 X in the holes in the opposite direction, said pin being 3,111,179 11/1963 Albers 175393 X adapted to be removed through said second hole. 3,129,777 4/ 1964 Haspert 175393 References Cited by the Examiner 5 36 317 6/ fg PATENTS 8 9 0 Great Britain. UNITED STATES PATENTS 349,835 12/1960 Switzerland.

1,209,393 12/1916 C b 11. 1 74 397 3 1932 i 2 5 3 5 CARL TOMLIN, P m y Examiner- 2,369,344 2/1945 Ehmann. THOMAS F. CALLAGHAN, Examiner. 

1. A DRILL BIT HAVING A PASSAGE FOR DISCHARGING FLUID FROM THE BIT, A NOZZLE DISPOSED IN THE PASSAGE AND THROUH WHICH FLUID IS DISCHARGED THEREFROM, SAID NOZZLE HAVING AN EXTERNAL TRANSVERSE GROOVE THEREIN, SAID BIT HAVING A FIRST HOLE ALIGNED WITH SAID GROOVE AND EXTENDING FROM A FIRST OUTER SURFACE OF THE BIT TO A LOCATION BEYOND SAID GROOVE, SAID BIT HAVING A SECOND HOLE OF LARGER CROSSSECTION THAN SAID FIRST HOLE INTERSECTING SAID FIRST HOLE AT A POINT BEYOND SAID GROOVE AND OPENING OUTWARDLY THROUGH A SECOND OUTER SURFACE OF THE BIT AND DISPOSED AT AN OBTUSE ANGLE TO SAID FIRST HOLE, SAID OBTUSE ANGLE FACING IN A DIRECTION AWAY FROM SAID NOZZLE, AND A HEADLESS RETAINING PIN INSERTABLE FROM SAID FIRST OUTER SURFACE INTO SAID FIRST HOLE, GROOVE AND SECOND HOLE TO RETAIN SAID NOZZLE IN SAID PASSAGE, SAID PIN HAVING A FIRST PORTION IN SAID FIRST HOLE AND GROOVE AND A SECOND PORTION IN SAID SECOND HOLE BENT AT A SUBSTANTIAL ANGLE TO SAID FIRST PORTION TO HOLD SAID PIN IN SAID HOLES AND GROOVE, THE MAXIMUM CROSSSECTION OF SAID PIN ALONG ITS LENGTH BEING NO GREATER THAN THE MINIMUM CROSS-SECTION OF SAID FIRST HOLE TO ENABLE SAID PIN TO BE SHIFTED COMPLETELY FROM SAID FIRST HOLE INTO 